A microcomputer-based precision impedance analyzer for measuring electrical impedance in plant tissues

1991 ◽  
Vol 71 (4) ◽  
pp. 1285-1288 ◽  
Author(s):  
M. I. N. Zhang ◽  
J. H. M. Willison
Keyword(s):  
Personal Computer ◽  
Electrical Impedance ◽  
Impedance Measurement ◽  
Impedance Spectrum ◽  
Plant Tissues ◽  
Impedance Data ◽  
Electrical Impedance Measurement ◽  
Measured Impedance ◽  
Lcr Meter ◽  
Precision Impedance Analyzer

A system for electrical impedance measurement in plant tissues has been built using a Hewlett Packard Precision LCR Meter controlled by a personal computer. This system is able to measure an impedance spectrum of 40 frequency points and automatically store the measured impedance data in the computer system within 30 s. Since this system is 1–2 orders more efficient than earlier systems for measuring impedance in plant tissues, it may have wide application in plant physiology. Key words: Electrical impedance, plant tissue, personal computer

Cadmium- and Flood-Induced Anoxia Stress in Pea Roots Measured by Electrical Impedance

2010 ◽  
Vol 65 (1-2) ◽  
pp. 95-102 ◽  
Author(s):  
Ildikó Jócsák ◽  
Magdolna Droppa ◽  
Gábor Horváth ◽  
Károly Bóka ◽  
Eszter Vozáry
Keyword(s):  
Electrical Impedance ◽  
Structural Changes ◽  
Structural Characteristics ◽  
Impedance Measurement ◽  
Cadmium Stress ◽  
Cadmium Accumulation ◽  
Invasive Technique ◽  
Plant Tissues ◽  
Electrical Impedance Measurement ◽  
Pea Roots

Electrical impedance measurement - complex resistance in the presence of alternating current - is a useful tool for the investigation of structural characteristics of solid materials but also for plant tissues. This measurement is easily done: only two electrodes are inserted into the plant tissue, so it can be considered as a non-invasive technique and it may be a successful method for detecting structural changes in plants caused by environmental stresses. The effects of fl ood and cadmium stress were investigated by electrical impedance measurement, because both of them cause structural changes in plant tissues. Apoplasmic resistance (Ra), symplasmic resistance (Rs), and membrane capacitance (Cm) of pea roots were calculated. In the fi rst fi ve days of fl ood treatment, the Rs and Cm values of roots decreased drastically. In case of cadmium treatment, the Rs and Cm values of roots showed an increasing tendency supposedly as a consequence of the enhanced membrane rigidity, the thickened cell walls and decreased growth phenomena caused by the heavy metal. There also was a remarkable difference in cadmium accumulation patterns and in the changes of the calculated parameters amongst anoxic and aerated seedlings. This initial work revealed that the development of stress caused by two environental stress agents, cadmium and fl ood, can be followed by electrical impedance measurement.

scholarly journals Practical Precision Electrical Impedance Measurement for the 21st Century – EMPIR Project 17RPT04 VersICal

2019 ◽  
Author(s):  
Oliver Power ◽  
Adam Ziolek ◽  
Andreas Elmholdt Christensen ◽  
Andrei Pokatilov ◽  
Anca Nestor ◽  
...  
Keyword(s):  
21St Century ◽  
Electrical Impedance ◽  
Impedance Measurement ◽  
Research Project ◽  
The Core ◽  
First Results ◽  
Electrical Impedance Measurement ◽  
Measurement Infrastructure

The core objective of EMPIR project 17RPT04 VersICaL is to improve the European measurement infrastructure for electrical impedance, with particular emphasis on the capabilities of developing NMIs and calibration centres. The project will seek to exploit the results of existing research on digital impedance bridges (DIBs) by designing, constructing and validating simple, affordable versions suitable to realise the impedance scale in the range 1 nF to 10 μF and 1 mH to 10 H with relative uncertainties in the range 10-5 to 10-6. The first results of the research project, including the bridge designs and details of a polyphase digitally synthesized multichannel source capable of providing voltage outputs of precise ratio and phase are presented.

Electrical Impedance Measurements of PZT Nanofiber Sensors

2016 ◽  
Author(s):  
Richard Galos ◽  
Xin Li
Keyword(s):  
Dielectric Constant ◽  
Material Properties ◽  
Electrical Impedance ◽  
Impedance Measurement ◽  
Low Frequencies ◽  
Impedance Measurements ◽  
Conductive Afm ◽  
Electrical Impedance Measurement ◽  
Microfabrication Techniques

Electrical Impedance Measurement of PZT Nanofiber sensors are performed and material properties including resistivity and dielectric constant are derived from the measurements. Nanofibers formed by electro-spinning with diameters ranging from 10 to 150 nm were collected and integrated into sensors using microfabrication techniques. The nanosensor impedance was extremely high at low frequencies and special matching circuitry was fabricated to detect output. The resulting impedance measurements are also compared with those of individual nanofibers that were tested using Scanning Conductive Microscopy (SCM) and Conductive AFM.

scholarly journals In vivo electrical impedance measurement in human skin assessment

2019 ◽  
Vol 91 (9) ◽  
pp. 1481-1491 ◽  
Author(s):  
Leszek Kubisz ◽  
Dorota Hojan-Jezierska ◽  
Maria Szewczyk ◽  
Anna Majewska ◽  
Weronika Kawałkiewicz ◽  
...  
Keyword(s):  
Human Skin ◽  
Electrical Impedance ◽  
Clinical Status ◽  
Impedance Measurement ◽  
Short Review ◽  
Non Invasive ◽  
Fish Collagen ◽  
Electrical Impedance Measurement ◽  
The One

Abstract Structural and chemical alterations in living tissue are reflected in electrical impedance changes. However, due to the complexity of skin structure, the relation between electrical parameters and physiological/pathological conditions is difficult to establish. The impedance dispersion reflects the clinical status of the examined skin tissue and, therefore, it is frequently used in a non-invasive evaluation of exposing skin to various factors. The method has been used to assess the effect of the fish collagen on the skin of patients suffering from the leg ulcer. Therefore, from a number of different approaches to skin electrical impedance dispersion, the one considered to be safe was selected and applied. This paper presents a short review of different technical approaches to in vivo electrical impedance measurements, as well as an analysis of the results and the effect of fish collagen locally administered on human skin.

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